A necessary step in the production of solvent refined coal (SRC) and other coal liquefaction products is a solvent fractionation or distillation step. Such fractionation is usually accomplished in a distillation tower at atmospheric or below atmospheric pressures. It has been found that the synergistic reaction which contributes to corrosion in the tower involves chloride containing species in combination with low boiling weakly basic nitrogen containing streams and phenols. These lower boiling nitrogen containing streams distill upwardly in the tower until they reach a level where they remain in solution due to a combination of boiling point and solubility factors. Chloride containing fractions flow down the column. The low boiling nitrogen compounds, by forming the amine hydrochloride, provide a means of holding the chloride in the tower thus allowing corrosion due to prolonged contact with the acidic hydrochloride species. The location of this amine hydrochloride formation depends upon the boiling point, solubility, and base strength of the amines on the particular tray within the tower. In general, though, the higher boiling heavier nitrogen compounds are more strongly basic and so tend not to form amine hydrochlorides. It is the presence of such amine hydrochlorides which contributes greatly to corrosion of tower materials. It has been found that the chemical makeup of the coal liquids within the fractionation tower are highly corrosive. Corrosion rates on the order of 1,000 mpy (mils per year) have been reported for stainless steel tower materials. The severity of this corrosion has required the relining, retraying, or total replacement of fractionation apparatus.